﻿using System;

class MatrixNumbers
{
    static void Main()
    {
        Console.Write("Please enter a positive integer number N (N < 20): ");
        string consoleInput = Console.ReadLine();
        int n;
        int.TryParse(consoleInput, out n);

        if (n > 0 && n < 20)
        {
            for (int row = 1; row <= n; row++)
            {                
                for (int col = row; col < n + row; col++)
                {
                    Console.Write("{0}  ", col);
                }
                Console.WriteLine();
            }
        }
        else
        {
            Console.WriteLine("Invalid  value!");
        }
    }
}
